Optimization studies on interfacial mechanical strength in the graphite-copper bonded structure for a divertor application

Residual stresses in the interface region were evaluated for the graphite-copper bonded system to assess the mechanical strength of the bonding interface. The normal stress components of the residual stresses around the interface edge were compared for three types of bonded structures such as a net-type, monoblock-type and saddle-type ones and were calculated to be 44 MPa, 7 MPa and 13 MPa, respectively. Consequently, the saddle-type structure was found to be favorable in the views of its mechanical integrity, fabrication ease and maintenance. The residual stresses around the interface edge in the saddle-type structures with the wedge angles of 45/spl deg/ to 135/spl deg/ were also examined. As the results, an optimal bonded configuration of the graphite-copper saddle-type structure was found to have wedge angle of about 60/spl deg/ for the least value of residual stress.